State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Bioresour Technol. 2022 Oct;361:127704. doi: 10.1016/j.biortech.2022.127704. Epub 2022 Jul 28.
Single cell protein (SCP) production by photosynthetic bacteria (PSB) is dependent on the bioavailability of carbon source, while sufficient volatile fatty acids (VFAs) in food waste fermentation liquid might be a potential alternative. It is unclear how the fermentation liquid affects the SCP biosynthesis and the related metabolic mechanism. This work demonstrated that the SCP production could be improved effectively (2088.4 mg/L) with high conversion capacity of carbon source (0.99 mg-biomass/mg-COD) by regulating carbon source level. PSB preferred to utilize the VFAs in food waste fermentation liquid. The carbon metabolic pathways (e.g., the transformation of VFAs to acetyl-CoA, and tricarboxylic acid cycle) involved in the SCP production were enhanced under optimal condition. Moreover, optimal carbon source regulation could significantly stimulate the environmental behaviour of PSB (e.g., two-component system, quorum sensing, and ATP-binding cassette transporter) involved in adaptation to external stimulus and maintaining high bacterial activity, resulting in SCP yield promotion.
光合细菌（PSB）生产单细胞蛋白（SCP）取决于碳源的生物利用度，而食物废物发酵液中充足的挥发性脂肪酸（VFAs）可能是一种潜在的替代品。目前尚不清楚发酵液如何影响 SCP 的生物合成及相关代谢机制。本研究表明，通过调节碳源水平，可有效提高 SCP 产量（2088.4mg/L），同时具有较高的碳源转化率（0.99mg-生物质/mg-COD）。PSB 更倾向于利用食物废物发酵液中的 VFAs。在最佳条件下，参与 SCP 生产的碳代谢途径（例如，VFAs 向乙酰辅酶 A 的转化和三羧酸循环）得到增强。此外，最佳碳源调节可显著刺激 PSB 的环境行为（例如，双组分系统、群体感应和 ATP 结合盒转运蛋白），从而有助于其适应外部刺激并保持高细菌活性，最终提高 SCP 产量。
